By Jeffrey Thomas, Anne Brody and Pamela Lee (June 20, 2017, 5:19 PM EDT) -- In general, communications between an attorney and his client relating to the filing and prosecution of a patent application are privileged. Last year, the Federal Circuit found that such communications between a patent agent and his client are also privileged.[1] But under the joint attorney-client privilege or the common interest doctrine, communications between attorneys and two or more clients may not be privileged in a later dispute between these clients. This article discusses the challenges that courts and companies continue to face in determining whether a party can access these patent prosecution communications in disputes: (1) between two joint owners; (2) between an employer-owner and an employee-inventor; and (3) with respect to a patent agent, in other Circuits and state courts....